Archery bows have been in existence in many forms for thousands of years. Many ancient civilizations had variety of shaped bows that gave the bow unique features and more power. In recent years, crossbows, compound bows, and recurve bows have also had many improvements to increase power, improve accuracy, decrease overall size and weight, and decrease the shock that the weapon produces during and after the shot. The shape of the limbs can have a significant impact on the displaced energy.